A bacteria culture doubles in size in 8 hours. How long will it take for the size to triple? Assume that the rate of increase of the culture is proportional to the size.
A) 12.7 hours
B) 13.1 hours
C) 13.5 hours
D) 13.9 hours
E) 14.3 hours

Question

Quizplus · Accepted Answer

The doubling time is 8 hours, so the growth rate k can be found using the formula 2 = e^(8k). Solving for k gives k = ln(2)/8. To find the time to triple, use 3 = e^(kt) and solve for t, giving t = ln(3)/k = ln(3)/(ln(2)/8) ≈ 12.7 hours.

A Bacteria Culture Doubles in Size in 8 Hours